The present invention relates to an automated gear change for an automobile vehicle, in particular for an industrial vehicle.
As is known, a gear change for an automobile vehicle comprises, according to a conventional configuration, an input shaft, an output shaft coaxial with the input shaft and coupled thereto with the possibility of relative rotation, and a geared transmission adapted angularly to connect the output shaft to the input shaft according to a plurality of transmission ratios defining a plurality of gears of the gear change itself.
The geared transmission generally comprises an auxiliary shaft or countershaft parallel to the input and output shafts, a plurality of first gears angularly idle with respect to the output shaft that can be selectively engaged on this output shaft and a plurality of second gears angularly rigid with the auxiliary shaft and coupled angularly to the respective first gears. One of the first gears is normally mounted in an angularly rigid manner on the input shaft and is angularly idle with respect to the output shaft because of its relative mounting between the input and output shafts; the engagement of this first gear on the output shaft makes it possible to provide the direct drive between the input and output shafts.
Known gear changes further comprise a plurality of sliding engagement sleeves interposed between relative pairs of first gears that can be selectively and independently actuated in order to make these first gears angularly rigid with the output shaft; each engagement sleeve is normally disposed in a neutral position, in which it does not interact with the first gears adjacent thereto, and can move between a first operating position in which it is displaced to one side with respect to the above-mentioned neutral position and engages one of the first gears adjacent thereto on the output shaft, and a second operating position in which it is displaced to the opposite side with respect to the neutral position and engages the other gear adjacent thereto on the output shaft.
The engagement sleeves are controlled by respective actuators, generally of pneumatic type, by means of respective actuation forks.
In more detail, the operation of the gear change is controlled by an electronic control unit, which receives a plurality of input signals from a gear selection lever and supplies as output a plurality of control signals for respective electrovalves controlling the actuators.
The automated gear changes of the type described above are in most cases formed by manual gear changes to which actuators and respective control electrovalves for the movement of the engagement sleeves are applied. These gear changes are therefore relatively expensive and complex since they include a relatively large number of components.
The object of the present invention is to provide an automated gear change for an automobile vehicle, in particular for an industrial vehicle, which makes it possible simply and economically to remedy the above-described drawbacks of known gear changes.
This object is achieved by the present invention which relates to an automated gear change for an automobile vehicle, in particular for an industrial vehicle, comprising:
an input shaft;
an output shaft;
a geared transmission interposed between these input and output shafts and including at least one auxiliary shaft and a plurality of gears mounted in an angularly idle manner with respect to at least one of these shafts;
engagement means associated with each gear that can be selectively actuated in order to make this gear angularly rigid with at least this one shaft;
characterised in that the engagement means comprise, for each gear, at least one engagement member mounted to slide in a first and a second seat that face one another and communicate and are associated with the relative gear and, respectively, with at least this one shaft, and can move between a first disengaged operating position in which it exclusively engages one of the first and second seats and a second engaged operating position in which it engages both the relative first and second seats, the gear change further comprising actuation means of electromagnetic type adapted to control the displacement of each engagement member between these first and second operating positions.